1. Field of the Invention
The present invention is directed to a twist valve used in association with a flexible, plastic container, such as a bag, pouch or bottle for the containment and delivery of a parenteral solution, such as diagnostic contrast media, drug formulations and nutrients to a patient in need of such parenteral solutions, wherein the twist valve provides for repeated access to portions or all of the parenteral solutions contained in the flexible container and wherein the flexible container, the parenteral solution, the twist valve and associated access means are autoclavable as a unit.
2. Reported Developments
Flexible medical containers designed for the delivery of parenteral solutions are most often referred to as IV infusion containers embodied in an IV bag containing a fluid to be infused into a patient. An IV line one end of which is integral with, or attached to the bag, and the other end of which is connected to a delivery means, such as a needle, serves to deliver the parenteral solutions to the patient. Typically, the parenteral solution is delivered to the patient by the gravitational force exerted on the IV bag which is elevated above the patient, such as illustrated in U.S. Pat. No. 5,391,150. The parenteral fluid flow is controlled with a valve which includes a resilient valve disc positioned in the parenteral fluid passageway which can be positioned to block the parenteral fluid or to allow the parenteral fluid to flow through the passageway.
Other control means for delivering medical fluids to a patient include force operative check valves such as illustrated in U.S. Pat. Nos. 4,114,617 and 5,025,829. Still other references include the use of resilient discs and resilient conical valve heads constituting part of check valves such as illustrated by U.S. Pat. Nos. 5,391,150 and 5,573,516.
Still another reference, U.S. Pat. No. 5,728,087, discloses a flexible container with multiple access means: a needle access port and spike access port penetrable by a needle or a spike; and an IV access port equipped with a one-way luer slip stopcock.
During administration of IV solutions it is often necessary to shut off the flow of the solutions allowing the medical practitioner to remove only part of the contents while preventing any leakage or spillage. This shut off function may be provided by connecting a pre-sterilized piece of tubing to the IV bag and then, adding a clamp or stopcock to the other end of the tubing. The addition of this implement to a pre-sterilized IV bag just prior to administration is cumbersome requiring aseptic handling of both the IV bag and the implement. The separate sterilization and packaging of the IV bag and the implement add extra cost and extra steps for use of the IV solution.
Alternatively, the IV bag with IV solution therein may be equipped with tubing having a clamp, valve or stopcock thereon, sterilized as a unit and packaged ready for use. However, many drug solutions can only be sterilized using an autoclave, or autoclaving is the preferred method of sterilization. Currently available valves cannot be sterilized by autoclaving without affecting their integrity and subsequent use.
Thus, there is a need for a valve integral with a pre-filled IV bag or other pre-filled flexible, plastic containers which is autoclavable together with the pre-filled IV bag or other pre-filled flexible containers as a unit ready for use in delivering parenteral solutions to the patient.